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Added support for O_RDWR and lseek() while writing.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2826 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Björn Stenberg 2002-11-11 13:57:58 +00:00
parent 1e524abd5b
commit 228605dc7b
1 changed files with 38 additions and 14 deletions
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52
firmware/common/file.c
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@ -38,11 +38,12 @@
struct filedesc { struct filedesc {
unsigned char cache[SECTOR_SIZE]; unsigned char cache[SECTOR_SIZE];
int cacheoffset; int cacheoffset;
unsigned int fileoffset; int fileoffset;
int size; int size;
struct fat_file fatfile; struct fat_file fatfile;
bool busy; bool busy;
bool write; bool write;
bool dirty;
}; };
static struct filedesc openfiles[MAX_OPEN_FILES]; static struct filedesc openfiles[MAX_OPEN_FILES];
@ -85,6 +86,7 @@ int open(const char* pathname, int flags)
openfiles[fd].write = false; openfiles[fd].write = false;
break; break;
case O_RDWR:
case O_WRONLY: case O_WRONLY:
openfiles[fd].write = true; openfiles[fd].write = true;
break; break;
@ -168,7 +170,7 @@ int close(int fd)
} }
if (openfiles[fd].write) { if (openfiles[fd].write) {
/* flush sector cache */ /* flush sector cache */
if ( openfiles[fd].cacheoffset != -1 ) { if ( openfiles[fd].dirty ) {
if ( fat_readwrite(&(openfiles[fd].fatfile), 1, if ( fat_readwrite(&(openfiles[fd].fatfile), 1,
&(openfiles[fd].cache),true) < 0 ) { &(openfiles[fd].cache),true) < 0 ) {
DEBUGF("Failed flushing cache\n"); DEBUGF("Failed flushing cache\n");
@ -250,12 +252,14 @@ static int readwrite(int fd, void* buf, int count, bool write)
int rc = fat_readwrite(&(openfiles[fd].fatfile), 1, int rc = fat_readwrite(&(openfiles[fd].fatfile), 1,
openfiles[fd].cache, true ); openfiles[fd].cache, true );
if ( rc < 0 ) { if ( rc < 0 ) {
DEBUGF("Failed read/writing\n");
errno = EIO; errno = EIO;
return -2; return -2;
} }
openfiles[fd].dirty = false;
openfiles[fd].cacheoffset = -1; openfiles[fd].cacheoffset = -1;
} }
else
openfiles[fd].dirty = true;
} }
else { else {
memcpy( buf, openfiles[fd].cache + offs, headbytes ); memcpy( buf, openfiles[fd].cache + offs, headbytes );
@ -265,6 +269,28 @@ static int readwrite(int fd, void* buf, int count, bool write)
count -= headbytes; count -= headbytes;
} }
/* if buffer has been modified, write it back to disk */
if (count && openfiles[fd].dirty) {
int rc;
DEBUGF("Flushing dirty sector cache\n");
/* seek back one sector to get file position right */
rc = fat_seek(&(openfiles[fd].fatfile),
openfiles[fd].fileoffset / SECTOR_SIZE);
if ( rc < 0 ) {
errno = EIO;
return -3;
}
rc = fat_readwrite(&(openfiles[fd].fatfile), 1,
openfiles[fd].cache, true );
if ( rc < 0 ) {
errno = EIO;
return -4;
}
openfiles[fd].dirty = false;
}
/* read whole sectors right into the supplied buffer */ /* read whole sectors right into the supplied buffer */
sectors = count / SECTOR_SIZE; sectors = count / SECTOR_SIZE;
if ( sectors ) { if ( sectors ) {
@ -273,7 +299,7 @@ static int readwrite(int fd, void* buf, int count, bool write)
if ( rc < 0 ) { if ( rc < 0 ) {
DEBUGF("Failed read/writing %d sectors\n",sectors); DEBUGF("Failed read/writing %d sectors\n",sectors);
errno = EIO; errno = EIO;
return -3; return -5;
} }
else { else {
if ( rc > 0 ) { if ( rc > 0 ) {
@ -305,7 +331,7 @@ static int readwrite(int fd, void* buf, int count, bool write)
if ( rc < 0 ) { if ( rc < 0 ) {
DEBUGF("Failed reading\n"); DEBUGF("Failed reading\n");
errno = EIO; errno = EIO;
return -4; return -6;
} }
/* seek back one sector to put file position right */ /* seek back one sector to put file position right */
rc = fat_seek(&(openfiles[fd].fatfile), rc = fat_seek(&(openfiles[fd].fatfile),
@ -314,17 +340,18 @@ static int readwrite(int fd, void* buf, int count, bool write)
if ( rc < 0 ) { if ( rc < 0 ) {
DEBUGF("fat_seek() failed\n"); DEBUGF("fat_seek() failed\n");
errno = EIO; errno = EIO;
return -5; return -7;
} }
} }
memcpy( openfiles[fd].cache, buf + nread, count ); memcpy( openfiles[fd].cache, buf + nread, count );
openfiles[fd].dirty = true;
} }
else { else {
if ( fat_readwrite(&(openfiles[fd].fatfile), 1, if ( fat_readwrite(&(openfiles[fd].fatfile), 1,
&(openfiles[fd].cache),false) < 1 ) { &(openfiles[fd].cache),false) < 1 ) {
DEBUGF("Failed caching sector\n"); DEBUGF("Failed caching sector\n");
errno = EIO; errno = EIO;
return -6; return -8;
} }
memcpy( buf + nread, openfiles[fd].cache, count ); memcpy( buf + nread, openfiles[fd].cache, count );
} }
@ -345,6 +372,10 @@ static int readwrite(int fd, void* buf, int count, bool write)
int write(int fd, void* buf, int count) int write(int fd, void* buf, int count)
{ {
if (!openfiles[fd].write) {
errno = EACCES;
return -1;
}
return readwrite(fd, buf, count, true); return readwrite(fd, buf, count, true);
} }
@ -369,13 +400,6 @@ int lseek(int fd, int offset, int whence)
return -1; return -1;
} }
if ( openfiles[fd].write ) {
DEBUGF("lseek() is not supported when writing\n");
errno = EROFS;
return -2;
}
switch ( whence ) { switch ( whence ) {
case SEEK_SET: case SEEK_SET:
pos = offset; pos = offset;